Association between poverty income ratio (PIR) and self-reported physical functioning (PF) among participants with systemic lupus erythematosus in the Georgians Organized Against Lupus cohort (analysis of complete data, n = 744).
| Outcome | Poverty Income Ratio | |||
|---|---|---|---|---|
| < 1.00 | 1.00–1.99 | 2.00–3.99 | ≥ 4.00 | |
| PF score, mean (SD)* | 36.20 (34.16) | 40.71 (35.38) | 55.45 (34.85) | 61.24 (34.75) |
| Difference in PF score (95% CI) | ||||
| Unadjusted | −4.50 (−11.31, 2.30) | 1.00 (ref) | 14.75 (7.62, 21.88) | 20.53 (11.48, 29.58) |
| Adjusted for age, sex, and race | −7.02 (−13.79, −0.25) | 1.00 (ref) | 13.09 (6.00, 20.17) | 20.62 (11.54, 29.69) |
| Multivariable-adjusted** | −6.02 (−12.81, 0.76) | 1.00 (ref) | 10.90 (3.25, 18.55) | 16.21 (6.39, 26.03) |
| Multivariable + SA-BILD score | −4.13 (−10.80, 2.55) | 1.00 (ref) | 10.91 (3.42, 18.39) | 13.47 (3.82, 23.13) |
| Multivariable + PHQ-9 score | −4.92 (−11.22, 1.38) | 1.00 (ref) | 7.99 (0.87, 15.11) | 12.34 (3.21, 21.48) |
| Multivariable + SLAQ score | −2.56 (−8.82, 3.69) | 1.00 (ref) | 6.51 (−0.55, 13.57) | 9.17 (0.08, 18.25) |
| Multivariable + BMI | −7.27 (−14.05, −0.49) | 1.00 (ref) | 10.51 (2.88, 18.13) | 16.02 (6.18, 25.87) |
PIR is ratio of household income to appropriate poverty threshold for household size, as defined by the U.S. Census Bureau (lower PIR indicates greater poverty).
↵* Scaled score of PF subscore from the 12-item Short Form Health Survey (scored 0–100, higher scores indicate better PF).
↵** Adjusted for age, sex, race (black vs not black), education, marital status (married vs not married), and disease duration. SA-BILD: Self-Administered Brief Index of Lupus Damage; PHQ-9: nine-item Patient Health Questionnaire; SLAQ: Systemic Lupus Activity Questionnaire (higher scores indicate more of the domain measured with these instruments); BMI: body mass index.